1. Field of The Invention.
The invention relates generally to small water craft and, more particularly, to apparatus for facilitating the boarding of the craft from an in-water position.
2. Description of The Prior Art.
In the prior art, the problem presented by the need to board a small water craft from the water adjacent to the craft has been recognized and various solutions have been devised. The type of water craft most affected is small personal water craft on which an operator sits astride a mid-section engine compartment and controls the craft directionally and otherwise from this position. These water craft have many of the general characteristics of larger motor boats including a stern panel (transom).
The small water craft referred to almost always includes water jet propulsion to eliminate external propeller blades and mounting structure as a matter of safety and immunity to damage. The so-called "jet ski" is a craft of the same general type, except that the operator is in the standing position.
The prior art known to the applicant includes U.S. Pat. Nos. 4,926,965; 3,986,503; 3,862,670; 4,738,642; 3,825,097; 4,979,454; 5,014,640; 4,556,125; and 4,191,388. Of these patents, the first four appear to be of most interest.
U.S. Pat. No. 4,926,965 to Fox discloses a self-retracting stirrup for mounting at the stern of a water craft. A spring arrangement erects a pivotally mounted stirrup assembly in response to initial forward movement of the water craft to remove it from water contact and thereby eliminate the drag which would result from continued contact between the stirrup assembly and the water. The disclosure of U.S. Pat. No. 4,926,965 does not apply to smaller water craft having jet propulsion. Such craft would not normally have a permanently mounted boat step from which this reference projects a stirrup structure. Still further, a structure which depends on initial water craft motion is not well adapted to water jet craft. If the structure were centrally mounted on the transom, the jet outlet would cause much undesirable splash and spray as it passed over the jet outlet. Mounting such a stirrup structure asymmetrically with respect to the transom center would apply a substantial undesirable roll force during boarding, that being undesirable in a small water craft.
U.S. Pat. No. 3,986,503 discloses a structure for mounting a large earth moving machine superficially resembling the invention; however, it includes a locking device which engages in response to operator positioning of a step platform generally horizontally. A disengagement force must be applied to the step platform to return it to the stowed position. Such a requirement would be quite burdensome in the water craft application.
U.S. Pat. No. 3,862,670 discloses a boat ladder which is extended into the water by the weight of a user in boarding the boat, but which automatically telescopes by spring action into a more compact form when the user steps away. The device is said to be adapted to stern of side mounting, but in a small jet water craft, rearward mounting would interfere with the water jet and side mounting would apply an unacceptable roll couple to the craft, particularly a small craft.
U.S. Pat. No. 5,014,680 discloses a step assembly for a boat which is shown mounted off-center on the water craft transom. The assembly is hand-operated and has no self-retracting feature. Mounting of such a device off-center on the transom would produce a very undesirable roll couple on a small water craft, and centered mounting is precluded by the interference potential with the water jet or propeller assembly.
U.S. Pat. No. 4,738,642 discloses a telescoping or hinged step for stern boarding of a small water craft, but does not provide self-operating means to retreat the mounting board(s).
The remaining references listed hereinabove are not pertinent to the structure and advantageous operation of the invention.
The manner in which the invention deals with the disadvantages of the prior art to produce a novel self-positioning boarding step at the transom of a water craft without propulsion jet interference will be evident as this specification proceeds.